Planet FGSW-2840 User Manual page 118

The Managed Switch with the lowest Bridge ID (switch C) was elected the root bridge, and the ports were selected to give a high
port cost between switches B and C. The two (optional) Gigabit ports (default port cost = 20,000) on switch A are connected to
one (optional) Gigabit port on both switch B and C. The redundant link between switch B and C is deliberately chosen as a 100
Mbps Fast Ethernet link (default port cost = 200,000). Gigabit ports could be used, but the port cost should be increased from
the default to ensure that the link between switch B and switch C is the blocked link.
The screen in Figure 4-5-4
This section has the following items:
■ STP Config
■ Port Config
■ MSTP Instance
■ STP Security
appears.
Figure 4-5-4: Spanning Tree Page Screenshot
Configure global configuration of spanning tree function.
Configure the parameters of the CIST ports for spanning tree function.
Configure the parameters of the MSTP Instance for spanning tree function.
Configuring protection function for devices can prevent devices from any
malicious attack against STP features.
User's Manual of FGSW-2840 / FGSW-4840S
118